"There aren't any grades," Musk said, explaining that instead of treating school like an assembly line "it makes more sense to cater the education to match their aptitudes and abilities."

Since that 2015 interview, Musk hasn't spoken publicly about Ad Astra, and families at the school have remained similarly tight-lipped. The school has no public website, phone number, or reference of the administrators and teachers who work at the school.

But Peter Diamandis, chairman of the X Prize Foundation, recently toured Ad Astra, and shared the ethos of the school. Diamandis' unique access to Ad Astra is likely due to the fact that Musk sits on the board of trustees of X Prize.

"One element that is persistent in that small school of 31 kids is the conversation about ethics and morals, a conversation manifested by debating real-world scenarios that our kids may one day face," Diamandis, wrote for the Huffington Post.

He went on to give an example of a question that teachers posed to students:

"Here's an example of the sort of gameplay/roleplay that I heard about at Ad Astra, that might be implemented in a module on morals and ethics. Imagine a small town on a lake, in which the majority of the town is employed by a single factory. But that factory has been polluting the lake and killing all the life. What do you do? It's posed that shutting down the factory would mean that everyone loses their jobs. On the other hand, keeping the factory open means the lake is destroyed and the lake dies. This kind of regular and routine conversation/gameplay allows the children to see the world in a critically important fashion."